There is known a type of food chopper having a conveyor in the form of an auger which presses food to be chopped axially against a face of a cutter die which is formed with an array of large-diameter holes. A cutter blade immediately adjacent the upstream face of this cutter blade serves to sever off pieces of the food being chopped which are forced into the holes so that pieces are pressed through these holes which have a size generally corresponding to the diameter of the holes. Downstream of this die and spaced therefrom is another cutter die formed with an array of holes having a much smaller diameter than those of the upstream die. A chopper blade is rotatable between the confronting surfaces of these parallel dies so that the intermediate-size chunks passing through the upstream die are reduced to smaller size and presses through the downstream die.
A considerable disadvantage of such a system is that pieces of bone or similarly hard material are able to pass through the upstream die but are then swept along the upstream surface of the downstream die, as they cannot fit into the small-diameter holes therein and are therefore not reducible by the blade. After some period of time of being swept around, this mass of hard pieces must be removed from the chopper, as it at least partially blocks the flow passage between the upstream and downstream dies. No successful arrangement has been proposed which eliminates the problem of comminuting or chopping hard pieces which pass through the upstream die in a two-stage chopper but which are unable to fit into the perforations in the downstream die.